This invention relates to a process for treating a radioactive waste, and more particularly to a process for treating a radioactive waste suitable for pulverizing solid matters discharged from a nuclear power plant, such as used ion exchange resins, etc. to powder.
Among solid wastes discharged from radioactive material-handling facility such as nuclear power plant, etc., solid wastes having a particularly high radioactive level are used filter aids and used granular ion exchange resins. The filter aids include cellulose and powdery resins. Since the ultimate procedure for treating the radioactive wastes have not been finalized yet, the used filter aids and used granular ion exchange resins are stored in a slurry state in storage tanks in the nuclear power plant. Storage of such radioactive waste in the slurry state causes serious problems such as corrosion of storage tank walls, etc., making it difficult to store the used filter aids and granular ion exchange resins for a prolonged period of time. Furthermore, tanks of large capacity are required for such storage of the solid radioactive wastes.
Study has been made to store the used filter aids and granular ion exchange resins in a more stable state. Since the filter aids and granular ion exchange resins are combustible, it has been tried to burn the used filter aids and granular ion exchange resins to reduce their volumes. However, the used filter aids and granular ion exchange resins contain much water inside, and thus their combustion is hard to make. When the used filter aids and granular ion exchange resins are burned, a filter is necessary for removing the radioactive materials contained in the resulting combustion gas as a flue gas. The filter must be more often exchanged with a new one, and a treatment of the used filter is required, and such treatment also produces a secondary radioactive waste. Thus, it is desirable to fill the used filter aids or used granular ion exchange resins in a drum and solidify them in the drum by means of cement, asphalt or plastics. However, in such procedure, the used filter aids or granular ion exchange resins keep the original shapes as filled in the drum, and a satisfactory volume reduction cannot be obtained.